first try to find out if there are pins shorted with solder since segment "E" + "R" and segment "F" + "H" are located next to each other on the PCB.

display-diner.JPG

Going from memory, failing resistor networks on the MPU can cause segment ghosting.

If you had an extra glass, I'd try touching it to the pins on the bottom display and see if you get the same ghosting. I'm guessing the glass is the problem because the missing segments are not showing any consistency. For example, when there's a "0" in digit 3 on the bottom board, segment h ghosts, but segment r does not whereas it ghosts on all the other ones. Digit 4 is missing the f segment when the number 4 is displayed but it displays in all the other places it should. Digits 8 & 10 miss the f segment on 0 and 4, and digit 8 misses the f segment on 8 & is weak on 9.

The upper display also looks to have an issue on digit 5 (segment g). If that glass is bad it could be dragging the strobes down.

The only thing the ghosting h & r segments have in common is that they (mostly) seem to ghost when their adjacent segments f & e are lit. Both those segments are driven through the 4049 hex buffer at U12. Since it has six separate buffers in it, it's possible two could be bad and the others ok, but if this was the case, I would think either the segment would be locked on or it would never come on. Which is why I think it's a glass issue.

viperrwk

The economics of these displays are such that when they fail, LED replacement is the only thing that makes sense. A single display glass on 6 or 7 digit displays, I could see replacing the glass.

The only consolation is you have four good 6118s and 7180s you could use in other displays.

viperrwk